/Engine/Source/Runtime/Engine/Public/MaterialExpressionIO.h
FExpressionInput
struct FExpressionInput
UMaterialExpres...
Expression
Material expression that this input is connected to, or NULL if not connected.
FName
InputName
Optional name of the input.
int32
Mask
int32
MaskA
int32
MaskB
int32
MaskG
int32
MaskR
int32
OutputIndex
Indexinto Expression's outputs array that this input is connected to.